Pavement.



T. S. HARRIS.

PAVEMENT.

APPLICATION FILED MAymleu.

1,280,995. Patented Oct. 8, 191s'.

2 SHEETS-SHEET 1.

T. s. HARRIS. PAVEMENT.

APPLICATION FILED MAY 11| 1911. 1,280,995.

Patented, 001;. 8, 1918.

2 SHEETS-SHEET 2.

mi TMQ/Zr THOMAS STEWART HARRIS, OF MINNEAPOLIS, MINNESOTA.'

r PAVEMENT.

Specification of Letters Patent.

Patent-ea oet. s, 191s.

Application led May 17, 1917. Serial No. 169,230.

To all whom t may concern:

Be it known that I, THOMAS STEWART HARRIS, a citizen of the United States, and a resident of Minneapolis in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Pavements, of which the following is a specification. i

My invention relates to pavements.

It is common practice to lay wood blocks contiguous to each other between retaining walls such as the side-or interior walls of buildings, the curbs of streets, the beams or girders of bridges, etc. Such blocks naturally expand under weather or induced moisture conditions. A limited amount of such expansion can be absorbed in the body of the pavement by spacing the blocks from each other, in common practice about a quarter of an inch, the space being ordinarily filled with a yielding pitchy substance. The amount of expansion which can thus be absorbed, however, is lrelatively small and in many instances the maximum space which it is practicable to provide between the blocks is far from being sufficient to absorb the expansion of the wood. In many uses also there is a serious objection to a pitchy filler between the blocks in that upon expansion of the wood the filler is forced out upon the tread surfaces of the blocks. Such situations are found in the floors of workshops and the like, and frequently also in streets. In cases of these latter kinds no means have heretofore been suggested that I am aware of for avoiding the injurious effects of block expansion. In many such eases heavy reinforced concrete building walls have been pushed out of plumb by the expanding blocks, it is -safe to say, as much as ten or twelve inches, and in roadways where the curbing has been strong enough to withstand the tremendous pressure the entire wood pavement has risen from its base so that the crown of the pavement has been sometimes live or six feet higher than its normal position. The upward extension of such pavements for a distance of several feet is quite common.

Such conditions of excessive expansion are not to be found in all localities, the same usuallv being due to the presence of a subsoil adapted to retain large quantities of water in association with the pavement for considerable periods; but the same kind turing or displacement of such walls for a length of time, the danger of excessive block swelling 1s always present, and in many mstances the retaining walls are under considerable strain at various times due to the expansion pointed out.

It is needless to say that where the pavement has buckled or swelled above its base the street must be closed to traflic, and that in most cases the relaying of substantially the entire affected area is required.

The principal objects of the present improvements are to provide a pavement susceptible of any degree of expansion whatsoever without injury to the retaining walls and without the loss of service of the principal portion of the pavement or floor; to provide means in a pavement which will at all times indicate to interested persons the amount of expansion actually taking place whereby suitable provision may promptly be made for maintaining the desired charactei' of the pavement without any substantial loss of service thereof; to provide means whereby the pavement may be readily and easily maintained in serviceable condition; and to provide means also which may be of simple form, easy of manufacture and installation, and which may constitute a part of the pavement itself without changing the general character of the tread surface thereof. Other objects and advantages will appear hereinafter.

In the accompanying drawings, which form a part of this specification, I have illustrated such means in combination with wood blocks and retaining walls of well known form. In these drawings Figure 1 is a sectional View illustrating the improved pavement or floor between walls of a building;

Fig. 2 is a fragmentary top plan of the pavement of Fig. 1; V

Fig. 3 is a sectional fragment showing the position of one of the expansion joint pieces after a relatively small amount of block expansion has taken place;

Fig. l shows in section the elements of Fig. 3 with one of the adjusting strips removed, the flat tread surface of the pavement being restored,

Figs. and 6 are fragmentary sections of the pavement of Fig. 1 showing how con-v tinued expansion of the paving is relieved` without pressure upon the retaining wall;

Y :tion between 'relatively fixed walls; Be-

tween the body of the pavement (comprising the blocks 10 and half blocks 10a) and the abutment walls 12 and 13 respectively I provide'a `pair of substantially telescoping expansion joint members 15 and 16, they being preferably wood pieces of considerable' length,v say eight to .twelve or more feet, the pieces being substantially rectangular in cross section in theA forms illustrated when normally together, as in Figs. 1, 2 and 4.

They extend along .the abutment wall'and form a marginal border for the pavement body. These two pieces 15 and 16 may be `blocks 10, and sawing theAk same diagonally,

as on the line 17, the line 17 preferably'not extending to the vertical .sides of the piece',

the angle or slant ofthe lineor surface 17V being such that the part 16 will slide or.

move upon the part 15 and whereby the vpart 16 will be directed against the wall, as 12, at such an angle that it will slide upward thereon when expansion of the wood forces the same beyond the position thereof shown in Fig. 5. y

The expansion joint pieces 15 and 16 are suitably positioned directly against the retaining wall, as 12. ln the form shown they constitute a part of the pavement itself. The blocks 10 and half blocks 10a preferably terminate on a line as 18, Fig. 2, parallel with the longitudinal edges of the expansion joint piece 16, which line may well be coincident with such edge, as shown at 19, Fig. 6. However, for purposes of more readily adjusting the pavement surface under relai tively slight expansion movements of the blocks I preferably provide one or more adjusting strips, as 20 and 21, preferably coeXtensive in length and height with the pieces 15 and 16 and lying between them and the main body of the pavement. From Fig. 3 it will be observed that under a relatively slight expansion the piece 16 is forced upward slightly, whereupon if one of the adjusting pieces, as` 20, be removed the part 16 will readily assume Vits normal positionas shown in Fig. L1. Under further expansion the strip 21 may similarly be removed. In

laying the pavement asuitable number of such Vadjusting strips may be employed to fill any space which may occur adjacent to the pieces 15 and 16, thus avoiding the necessity of trimming off the ends of blocks Referring to Fig. 7, the curb 2.5, base 26, and block 10 are of well known form and construction The expansion joint pieces 15 and 16 and the adjusting strips 20 and 21 are of the same form respectively as in the other figures. The functions'and operations of the parts are also the same as thosev already described. f l

A particularly important featureof-these improvements is in the fact that under continued andexce'ssive eXpansion'of the blocks the retaining walls, as 12, 13 or 25, or of whatever form they may be, are at all times relieved from pressure, the expansion strains beingdiverted from such walls, the Ipieces or blocks one afterthe other riding upward l upon the slanting surface 17 upoirthev eX- pansion joint piece 15, suchparts and blocks, inthe absenceof any attention on the part of interested persons, simply creepingl up along the wall, falling over, and Vforming a row of loose blocks along theedge of the pavement, at a place where they are substantially out ofthe path of trafic or, in a building, away Vfrom the floor lspace being 'occupied Thus the efficiency of the floor`V orroadway is not destroyed or seriously if at all affected by any such expansion strains..

According'to these improvements repairs following' excessive expansionmay be made most expeditiously and at relatively slight cost, itbeing simply necessary to reform the edge of the block paving into a substantially straight line, using the half blocks 10a there present, inserting one or more strips 20, 21 as required, and replacing the sliding joint member 16. Y y

Another feature of advantage is in the fact that interested persons are promptly informed by the elevation of the part 16 that expansion of the pavement is taking place, whereupon such attention to the pavement or to yconditions affecting its expansion'may be given as the occasion may suggest. Thus, for instance, in shops so vpaved excessive sprinkling of the pavement with water may be avoided when undue expansion is being occasioned thereby. It sometimes happens that automatic sprinkler systems Hood such floor surfaces, and, where the pavement has been constructed according to hitherto practices, before interested persons became aware of danger from block expansion the retainthe pavement are maintained in a pavement made according to the improvements herein set forth.

The invention is not limited to the construction specically illustrated and described herein, and I contemplate all modiications and departures therefrom as fall within the scope of the appended claims.

I claim:

l. The combination of wood blocks forming a pavement body, an abutment wall spaced from said body, and an expansion joint device between the abutment wall and said pavement body with paving blocks contiguous to the joint device, said expansion joint device including a member having a surface slanting upward toward the abutment wall over which slanting surface the paving blocks contiguous thereto will slide under the influence of expansion of the paving body.

2. The combination of wood blocks forming a pavement body, an abutment wall adjacent thereto and spaced therefrom, said paving body terminating in a line substantially parallel with the abutment wall, and an expansion joint device between the abutment wall and the pavement body and adapted to divert from the abutment wall expansion strains developed in the pavement body, said expansion joint device including a pair of intertting wood pieces having coperating sliding surfaces normally on an upward incline toward the abutment wall, the inclination of the piece adjacent to the abutment wall being such that paving blocks in 'the paving body adjacent thereto will slide upward thereon under expansion strains.

3. The combination of paving blocks forming a paving body, an abutment wall adjacent thereto and spaced therefrom, an expansion joint piece extending along the abutment wall and having an upwardly inclining surface and positioned between said wall and the pavement body, a second expansion joint piece having a similar slanting surface resting upon the slanting surface of said first mentioned expansion joint piece, said expansion joint pieces forming a marginal border for the pavement body.

4. The combination of paving blocks forming a pavement body, an abutment wall adjacent thereto and spaced therefrom, the pavement body having an edge portion substantially parallel with the abutment wall, a pair of coperating expansion joint pieces between the pavement body and the abutment wall, said pieces having facing surfaces extending upwardly toward the abutment Wall, and an adjustment piece in strip form also between the abutment wall and the pavement body.

5. The combination of an abutment wall, a base for a pavement extending to the abutment wall, a wood strip running along said abutment wall and resting on sald base, said strip having a surface inclining upward and toward the wall and, forming an angle with the bottom of said. strip, a second strip resting upon the first mentioned strip and adapted to slide on said inclined surface, and wood pavement elements contiguous to said second mentioned strip, the arrangement being such that upon expansion of said pavement elements said second strip is forced upward on said slanting surface whereby such strains of expansion are diverted from the abutment wall.

THOMAS STEWART HARRIS.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

